Herbal Root Canal Irrigating Solutions: A Systematic Review of Antimicrobial Efficacy and Clinical Evidence

Abstract

Background: Root canal irrigation is a critical component of endodontic therapy for eliminating microorganisms and organic debris. Sodium hypochlorite remains the gold standard; however, concerns regarding cytotoxicity, unpleasant taste, and the risk of tissue injury have stimulated interest in herbal alternatives.

Aim: To systematically review and critically appraise available evidence on herbal root canal irrigating solutions with respect to antimicrobial efficacy, antibiofilm activity, clinical effectiveness, and safety.

Materials and Methods: A systematic search of PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar was conducted for studies published up to December 2024. In vitro studies, animal studies, and clinical trials evaluating herbal irrigants used during root canal treatment were included. Risk of bias was assessed using the Cochrane RoB-2 tool for randomized controlled trials and a modified methodological quality checklist for in vitro studies. Due to substantial heterogeneity, data were synthesized qualitatively.

Results: Fifty-four studies met the inclusion criteria, including 14 clinical trials, 6 animal studies, and 34 in vitro studies. Commonly investigated herbal irrigants included Azadirachta indica (neem), Morinda citrifolia (noni), propolis, Triphala, green tea polyphenols, Aloe vera, curcumin, and Nigella sativa. Most herbal irrigants demonstrated significant antimicrobial activity against Enterococcus faecalis and other endodontic pathogens in vitro. However, sodium hypochlorite consistently showed superior tissue-dissolving and broad-spectrum antimicrobial efficacy. Clinical evidence was limited and heterogeneous.

Conclusion: Herbal root canal irrigants exhibit promising antimicrobial properties and favorable biocompatibility; however, current evidence is insufficient to support their use as standalone alternatives to sodium hypochlorite. Well-designed, standardized clinical trials are required.